Laser ceilometer dynamic threshold selecting method based on pulse echo forms

Abstract

The invention relates to a laser ceilometer dynamic threshold selecting method based on pulse echo forms, and belongs to the field of laser remote sensing. The laser ceilometer dynamic threshold selecting method based on the pulse echo forms solves the problems that in an existing threshold selecting method, only extreme point positions or fifty-percent peak point positions or dual-threshold positions of pulse echoes are adopted to confirm transition time of laser pulses, the selected thresholds can be only suitable for specific measurement conditions or plane targets of small slopes. According to the laser ceilometer dynamic threshold selecting method based on the pulse echo forms, a mathematic model of the laser ceilometer pulse echo forms, noise standard deviation and threshold rising edge moment variance is regarded as a theoretical basis, the range error minimization of a laser ceilometer serves as a basis, and the optimization selection of the threshold coefficient of the laser ceilometer is achieved through a parameter iterative search method. The influences of noise and pulse widening introduced by gap title effects of the plane targets are fully considered in the threshold value selection method, range errors caused by threshold setting can be reduced, and the satellite-borne laser ceilometer can complete high-precision laser ranging of the plane targets of different slopes under different measurement conditions.

Description

technical field [0001] The invention belongs to the field of laser remote sensing, and in particular relates to a method for selecting a dynamic threshold value of a laser altimeter based on a pulse echo form, which is suitable for high-precision acquisition of distance measurement values ​​of a spaceborne laser altimeter. Background technique [0002] The laser altimeter is an active laser remote sensing device, which is mainly composed of two parts: the transmitting system and the receiving system. The laser altimeter pulse echo is the electrical pulse echo signal obtained by receiving and processing the laser pulse echo by the receiving system after the laser pulse signal emitted by the transmitting system is transmitted through the atmosphere and scattered by the target. The establishment process of laser altimeter pulse echo is as follows: figure 1 shown. In view of the target tilt effect and the influence of system parameters, the pulse echo will be broadened to a ce...

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Problems solved by technology

[0011] The present invention mainly solves the technical problems existing in the prior art; it provides a method to realize the dynamic detection of the laser altimeter based on the minimization of the ranging error of the laser altimeter under the comprehensive consideration of the noise level and echo broadening. The optimal selection of the threshold enables the spaceborne laser altimeter to complete the high-precision laser ranging of different slope plane targets under different measurement conditions. The dynamic threshold selection method of the laser altimeter based on the pulse echo form

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